Furnace.



J. F. MONNOT.

FURNACE. APPLICATION PILED,NOV.13, 1906.

WITNESSES Patented Oct. 27, 1908.

asnnmsqmsm 1.

iNVENTOR C TMQMAEt AT EY Ta Y J. P. MONNOT.

FURNACE. APPLICATION FILED NOV.13, 1906.

901 ,986, Patented Oct. 2'7, 1908. I

3 SHEETS-SHEET 2.

fl. 1: l WITNESSES 6 T 'W JBRHT. ch fmh t I m 9 I BY @4 QMMM Mme) ATTORNEYS a W'ITNESSE J. F. MON

PU I APPLICATION 1 NOV. 13, 1906.

901,986,- Patented 0011 211908.

3 SHEETS-SHEET 3.

INVENTOR :sZPMTMM 0+ ATTORNEY I To all whom may; concern:

uiviTED STATES PATENT. orrion JOHN F. MONNOT, or

FURNACE.

Be it known that 1, JOHN F. MN1\ 0T, a

citizen of the United States, residing at New York, in the county of New-York and State of New York, have'invented certain new and useful Improvements in Furnaces; and I do hereby declare the following to be a'full,

(clear, and exact description of the' same,

such as will enable others skilled in the art Specification of Letters-Patent.

. f Application filed November 13, 1906. Serial No. 343,248.

to which it appertains to make and use the SELIDB.

My invention. relates to impr'ovements in-- furnaces, and particularly to that type thereof wherein heating chambers such as crucibles, more especially very large crucibless, and like objects, are to be heated to a very-high temperature by means of a flame jet, such for example as that from an oil or gas burner.

My invention consists in means for distributing the flame and'heat with approximate uniformity around the heating chamber oi crucible or like object, so as to heat the same with approxlmate uniformity on all sides; in means'for radiating heat down upon the metal in such heating chamber while protecting the metal against contamination; and in other features of invention as more fully hereinafter set forth.

- Theobjectsof my. invention are to obviate the uneven heatmg heretofore characteristic of gas or oil crucible furnaces and the like; to prolong the, life of the crucibles or like objects and avoid local over-heating and burning out thereof; to distribute the flame andheat with substantial unlformity around the crucible or" like object. to be heated; to heat molten metal-hand the like to very high temperatures; to avo1dcontamin'ation of the metal while heating the same from the surface; to adapt the furnace-for the introduction of articles into the molten metal without contamination of-or injury to either such articles or the molten metal itself; and generally toproduce a furn'ace which, while capable "of heating cruel bios and like articles and the contents thereof to very high temperatures, shall be simple, easy to. operate, economical of fuel, and easy to construct and maintain.

In the heating of large crucibles and mo]- ten metal contained therein to hightemperatunes, I have found it," exceedingly difficult to avoid local. overheating of the crucibles by the methods heretofore known, while ob Patented Oct. 27, 1908.

tainingthe desired high temperatures, and

have found that the crucibles have only a NEW YORK, N. Y.,,ASSIGNOR TO DUPLEX METALS COMPANY, or NEW 'Y K, 1N. Y., A CORPORATION OF NEW YORK. I

lation of flame gases and products of combustion'; I'Ieat'is produced by a-fla-me' jet projected into said chamber from a gas or oil burner. The flame jet must not be allowed to play directly upon the crucible, of course, and various attempts have been made todiifuse or scatter the flame; but I have found that evenyheating of the-crucible is impossible by the means hitherto employed ordinarily for this purpose, local overheat,-

ing taking place at some point, with the rev sult that the crucible soonweakens there and breaks; and it may easily, and does frequently, happen,. that while the crucible is overheated at someone point, the crucible as a whole and its contents are not heated peratures. If the flame jet be split by a plow or dividerand caused to flow around the crucible, the highest temperature is developed at the back of the crucible, where the divided flame currents come together hot enough to produce the desired-high temi again, and the crucible is exceedingly apt to fail at.this point after. a very short period of use. To overcome these difficulties, I have provided reflecting surfaces in the direct line of impingement of the flame or' in the'path .of diverted or reflected portions of the flame,

wherebyany desired'portionlof the flame may be 'reflected'back, or to one sid-eiozflin any direction desired, against the sides -,of the furnace chamber and fromthence toward or around the crucible. And I have further provided, in the rear portion of the furnace chamber, reflecting surfaces for reflecting back from such portion of the furnace,

where there is apt to be an excess of flame ases ortions oft heflame" ases and so dis- 7 g 9 tributing such'flame gases to those portions of the furnace chamber'where otherwise the heating effect would be less than is desirable." Thereby I have beenable'to obtain substantially uniform heating and to heat both the 'crucible and its contents to a very high temperaturewithout local overheating and with very material lengthening of the life of the cruciblefor this reason.

, I may also provide means for performing a considerable portion of the heating of the contents of thecrucible by heat radiated down from a refractory roof through a body of-inert gases by which the metal is pro tect d from contact with the flame gases.

The accompanying drawings illustrate cer-= tain forms of crucible furnaces embodying my s'aidinvention.

In said drawings: zontal section of a crucible furnace. con- .stru'cted in accordance with my] invention,

the section being taken below the bottom of the crucible, on the line l1 of Fig- 2. Fig. 2" shows a. central vertical section of such furnace, on the line 22'of Fig. 1.

1 Fig. 3 shows 'a'- front elevation of the flame distributer' of my furnace. I are sectional views of an alternative form of furnace embodying the same. principles,

Fig. l showing a horizontal section through the cover of the furnace on the line H of I*ig .-5,and Fig. -5.showing a central vertical section of said furnace; Fig. 6 is a View similar to F ig.4, but illustrates the use of separate burners for the upper part. of the furnace; and Fig. 7 is a central verticalsec tion of the upper part of a furnace provided with such separate burners Fig. Sis a llOIl-J zontal section through thelowerp'art of'the furnace shown in Figs. 4 and 5, and illus-:

tra-tes particularly-the stepped reflecting surfaces in the back wall of the combustion chamber. 4. Fig. 9 shows an outside elevation of the furnace, and in particular indicates means for raising and lowering the isolating sleeve.

Referring 1 designates the furnace walls inclosing the combustion chamber 2, and 3 designates a crucible within said chamber, resting upon a pedestal, and having a flange 5 luted to tliewalls 1 so as-to form a substantially tight joint. The said crucible, when in use,

' is commonly keptcovered by a cover 6 ex cept when it is necessary the crucible.

7 designates aburner adapted to" project to obtain access to I a flame jet through a port 8' into the combustionchamber 2. This flame jet does not impinge upon the crucible itself, but upon a distributer 9, which also forms the pedestal for the crucible. The flame jet striking this pedestal, is caused to divide and pass therearound in two streams. I have found, however, that the mere division of a flame in this manner, so'that itwill flow around beneath the base of the crucible,is notenough to insure even heating of the crucible; but to the cont1fl1y,lll1&i3 where the divided currents meet,

a zone of intense temperature is produced,

unless othermeans be provided to effect a Figure 1 shows a hori Figs. ,4 and si'desv of said pedestal.

, first to Figs. '1 to inclusive, illustrating my furnace in its simplest form,

further diffusion and distribution of the I To this end, I- provide the dis-.

flame gases.

tributer or pedestal 9 with a plurality of;

reflecting faces-0r facets, against some of which portions of the flame, will impinge directly and will be reflected thereby against the walls of the chamber 2 or against other facets and re-reflected therefrom some of these-facets being arranged to reflect the flame im in in thereupon 'ust to the ri ht and P g g l e left oftheentrance port 8, others to reflect otherportions of the flame still farther to 'the right and left, and so on; the portions of the flame so reflected against the walls of chamber 2 being in turn reflected therefrom'toward the sides, or upward, or both toward the sides and upward, according to .the angle ofimpingement; The first of'these facets of pedestal 9'is a rounded .chamber 2 just above the entrance port 8; from which wall such portions of the flame 'are in turn reflected upward toward and along the front of the crucible.

. .On either side of nose. 10 is a facet 11, de

signed to receive direct impingement of side portions of the flame and to reflect the flame so impinging against the'wall of chamberQf to'right and left of entrance port 8, and also to receive portions of the flame reflected from nose 10- and reflect same still farther to the right and left of'the entrance port.

The iipper portions of facets 11 are inclined..

surfaces-or facets 11 which reflect the flame strikii'ig thereon upward as well as towardv the sides of the chamber. The portions of the flame reflected from facets 11 against the sides of the chamber are in turn reflected toward the sides of said, chamber.

of flame gases which have not been reflected cannot be predicted exactly on-the linesof optical reflection, but on the other hand the interference between the various flame currents and branches'thus produced in itself tendsto keep a. considerable portion of the During these successive reflections the, branches-ofthe flame affected are of course expanding and rising; moreover the direction of such branches is affected greatly by the currents but. are flowing 'aro und,the pedestal, for j which reason the distribution of the flame flame within the front and side portions of I the combustion chamber and so to distribute the heating effect as desired.

The. portions of the flame reflected from facets ll are subject to re-reflection, expan-.

sion, and interference with other flame currents flowing around the pedestal and base of the crucible in much the same manner, but are reflected above those portions 1 of the flame reflected from facets 11, and 'so heat the portions of the crucible to the right and left ofthe front, but not far from the front.

Other facets 12, 12, and 13, 13, reflect other portions of the flame in a similar manner.

There may, in fact, be, as many of these facets, as desired, and they may be arranged 111 various different ways. The arrange-. ment of facets shown in the drawings 18 one which has been found to give very even distribution of the flame.

Owing to the space afforded for expansion and combustion of the fuel, and the very perfeet mingling of fuel and air due-to inter-' ference between different currents, swirls,

and the like, the bulk of the combustion will be complete before the flame reaches the vicinity of the sides of t e crucible, and the flame gases will be so loa ed down withCO' that relatively little combustion of the mateflection and re-refiection of different portions of it, as described, preventing overheating of any part of the crucible, is also a most potent factor in prolonging the life of the crucible.

Furthermore, much of the heat energy of the flame is reflected'as radiant energy or heat from the walls of the. chamber 2, such heat being very effective so-far as the heating of the crucible is concerned, but of, course not tending in itselfto oxidize or wear away the In fact, there isno direct cont'actof the flame with the walls of.

walls of the crucible.

the crucible until combustion .is so nearly complete that the destruction of the crucible walls will be very slow. To preventdirect cont-act of the flame with the Walls of the crucible before combustion is nearly completed,

I make the upper portion of the pedestal 9,

above the facets mentioned, a flaring deflec- .tor 14. Further, to scatter the at the extreme back of the furnace I provide a baffie lug 15, which prevents the bulk of the two flame currents meeting at the back of the furnace until well above the bottom of the cru cible. Theflame gases escape throughports 16.

A very good flame distribution may be obtained by merely providing facets in the pedestal itself as shown in Fig. 1, 2 and 8. But a still better distribution may often be obtained by providing somewhat similar facets 17in the rear wall of the combustion chamher 2, asindicated in Figs. 5 and 8 these lat ter facets being commonly produced by causing certain of the bricks of the lining of the combustion chamber to project out farther than others. It is uotso essential to arrange these facets according to a definite system as is the case with the facets at the front-of the crucible, as the purpose of the rear facets 17 around toward the sidesof the chambe1flincrucible,

reflect considerable portions thereof forward or to the sides, with a view to causing interference of, flame currents at points well stead of at the extreme Backthereof. The material of which crucibles must be formed is well known to be a very poor heat conductor, and for this reason it is def -si'rable to supplement the transmission of heat'throughlthe crucible walls, by heatingfrom the surface of the body of metal in the Many metals, however,-are subect to excesslv'e deter oration bythe action of the flame gases and other gases-present 1n -the combusionf chamber; and this is espe;

cially. the case, with certain metals, when, saidmetals areheated far above their melttrate means whereby. such" surface heating may be eifectedtbyradiation of heat from a refractory roof without direct contact of the flame and furnace gases with the molten 'ing points. In Figs. 47 inclusive I illusmetal, such metal in fact, being protected 4 from suchcontact bya body of "inert-gas through which,v however, radiated heat passes freely. In these figures, 19 desi nates a cover for the furnace, lined with refractory material and inclosing above the" crucible a heating chamber 20 the roof of which is the surface of the refractory lining ofcover 19. N ear'the center of this chamberis an annular space 21 from which lead. escape passages 22; andifor obtaining access to the interior of the crucible for charging or other reasons and for introducing articles into the'molten metal, I provide a sleeve 23 of refractory materia In the construction shown in Figs. it-and 5, ports 24 are provided in the wallsl, registering with other spiral ports in the cover'19, and arranged to conduct flame gases from chamber 2-and pro3ect same obliquely and approximately tangentially against the roof of the combustionchamber 20, such gases being thereby caused to swirl around insaid chamberalong-the surface of such roof, finally passing into the annular exit space'Ql and thence out. ,fAJbody of inert gases '(consisting substantially, if not entirely, of CO will collect in the lower partof this chamberQO andjust above thef surface of the molten metal; and such inert gases do not have a particularly detrimental influence on many molten metals, while they do serve to exclude air, or other oxidizing.

gases,- and Cf) and hydrogen or hydrocar-' bons (if any) as well as nitrogen, which gases have a curiously detrimental influence j upon many metals. But while the flame gases do not reach the molten metal, the heat produced by them is radiated from the roof of chamber 20 downward through the, body of inert aset inthe lower part of the said 'chambitib'ffhe surface of the molten metal, at least to any considerable distance,

b fi-t on the other hand, the. sleeve-should be able to follow the molten metal; also, when heating up, this may be done most efficiently byraising the sleeve to, or near, the top of 1 Chamber 20'. Therefore, I arrange this sleeve to move vertically, as indicated in Fig.0, providing a pivoted lever 27 connected to said sleeveby links 28, and-carrying'a counterweight 29."

":In another application for Letters'Patent,

filed Dec. 26, 1905, No. 293,409, I have claimed the isolating sleeve 23, and therefore I'do not claim the same broadly herein.

hat I claim is I 1. A flame heated furnace provided with flame producmgmeans and comprising a furnace chamber and, W1th1n thesame, a

body ofrefractory material having a plurality of reflecting faces arranged 1n steps laterally, one behind the other, said stepped faces being in impinging relation to the flame from said flame-producing means.

2. A flame heated furnace provided with flame producing means and comprising a furnace jchamber and, within and near the base of said chamber, a faceted face of ref1'"actor material having stepped lateral facets, a plurality of said facets being in impinging relation to the flame from said flame producing means and the facets being so placed with regard to the furnace chamber walls as to cause an approximately uniform upward movement of flame gases in said chamber.

3. A flame-heated furnace provided with flameintroducing means and a support for a 'heating chamber, said supportat its base being provided with faces having facets at different angles and said faceted faces being in impinging relation to the flame produced by said fl2l111Ql1ltIO(l11Cl11g means.

4. A flame heated furnace provided with flame introducing means and a support for a heating chamber havmg an overhanging upper edge and a faceted base thereunder in impinging relation to the flame produced by said flame introducing means. I

5. A flame heated furnace provided with flame introducing means and a-support for a heating chamber having an overhanging upper edge and a faceted base thereunder in nnpmging relation to the flame produced by said flame introducing means, the facet in the direct line of said flame being rounded. 6. A flame heated furnace provided With flame introducing means and a support for 8. A fl'ame heated furna'ce'p ovided with flame introducing means and W1 afaceted pedestal adapted to support a heating chamber therein, the facet in the direct line of impingement of the flame being rounded and the facets on either'horizontal side being plane-surfaced, each successive sidefacet being shorter horizontally than the one preceding. 1

. 9. In a flame heated-furnace, a support of refractory material for a heating chamber, said support provided With angularly related facets in its forward side and a rounded rear side. r

10. Ina flame heated furnace, the combination of a furnace casing of refractory material, means for introducing flame therein, a support for a heating chamber Within said casing having a faceted face in line with said flame introducing means, and a flamed'iverting body in the interior of the casing behind said support. I

11. A flame heated furnace comprising a,

furnace chamber, means for introducing flame theremto, a support for a .heatmg chamber In impinging relation to the flame produced by said flame introducing means,

said support being faceted to cause even distribution of flame around the heating ChillIl ber, and means for introducing heat at a point above the heating chamber and out of impinging contact with the top thereof.

12. In a furnace, a flame chamber, a heating chamber therein,.flame introducing means for the flame chamber and means for introducing hot gasesia'bove the heating chamber but out of contact-With the top of sald heat mg chamber. a

ing chamber-therein closing the top of the 13. In a furnace,1a flame chamber, a heat flame chamber but spaced away from. its;

walls, an arched-furnace cover above the heatmg chamber and one or more burners for directing hot gases against the arch in heat radiating relation to the top of the heating chamber but out of direct contactwith such top.

' formed by said cover.

i l. "In a-furnace, the combination of a casiarranged to project portions of the flame 5 ing, a heating :chamber suspended therein and closing the. topoffthe' same, and a re: movable cover above said heating chamber, said casing and: cover having coiiperating passages'intheir walls adapted to abstract hot gases from the space around the heating chamber and deliver same -116Xt 15. A furnace comprising a'flame'chamber, aheating chamber therein, a removable furnace cover above the heatlng chamber, and a sleeve arranged to extend down through the cover toward and into the top of said heat: ing -chamber.

16. A furnace comprising a flame chamber,

a heating chambertherein, and a cover above the heating chamber andprovided with a sleeve arranged to QXQend down through it toward the top of saidheat'ing chamber, said. cover having also means for passing hot gases along its-roof and an annular space around said sleeve for the escape of such; gases.

chamber, means for introducing flamefhere in and a flame-diverting element projecting upwardly from the floor of the chamber in line with the flame so introduced and provided with a plurality of stepped lateral refleeting facets.

18. In a flame heated furnace, a furnace chamber, means for introducing flamethereupwardly from the floor of the chamber in line with the flame so introduced and having flame passages around 1t, said element being provided with facets, certain of which are substantially vertical, others inclined from the vertical, and one of which is a curved dividing facet.

20. A furnace comprising a furnace chamber and flame diffusing and distributing emeans therein spaced away from the walls of such" chamber and adapted to have flame directed thereagainst and comprising a series of reflecting facets arranged to receive the impingement of said flame and to reflect same against the walls of said chamber.

21. A furnace comprising a furnace chamber and flame diffusing and distributing means therein spaced away from the walls of such chamber and adapted to have flame directed thereagainst'and com rising flame dividing means and flame-distributing facets the roof chamber.

17. In a flame heated furnace, a furnace toward the center.

approximately transversely of the natural flow of flamepast said diffusing and distributing means. a 22. A furnace comprising flame introducing means, a furnace chamber, and'flame diffusing and distributing means therein and I spaced away from the wall of such chamber located in the path of the flame so introof the flame-toward thewalls of said chamber.

ing means, a furnace chamber, and within said chamber and 1n thepath of said flame 'a flame distributer provided with aflame- 23.- Afurnace comprising flame introducdividing portion and on either side thereof flamerreflecting facets arranged 'to reflect flame impinging thereagainst toward the front and side portions of the walls of said A- furnace comprising'flame introducing means, afurnace chamber, and within said chamber and in the path of the flame a flame (listributer provided with a flame dividing portion having above it an inclined reflecting facet, and on either side thereof vertical and inclined reflecting facets. ar-

ranged to reflect flame impinging .thereagainst toward the front-and side. portions of the walls of said furnace.

25. A furnace COIIlPIl'Slllg flame mg means,'a furnace chamber, and within said chamber and in the path of the flame a pedestal having reflecting 'facets arranged to reflect flame toward the front andside portions of the walls of said furnace, the

walls of said chamber toward the rear thereof having other reflectin facets.

26. The method of 'di using heat in furnaces, whichconsists-in projecting a flame jet into a furnace and in dividing said jet intobilaterallysymmetrical streams and refleeting portions thereof backward and more or less laterallyand transversely of the direction of natural" flow of the divided flame currents. I f

27, The method --.of diflusing heat in furnaces; which consists in projecting a flame jet into a furnace, dividing said jet into bilaterally symmetrical streams, reflecting poitions of each stream approximately transversely of the direction ofnatural fiow of the divided flame currents,'and re-reflecting such reflected flaine portions upward and In testimony whereof I aifix my signature, in the presence of two witnesses.

. JOHN F. MONNOT. Witnesses:

' ROGER H. LYON,

HARRY M. MARBLE.

introduc- 

